Please describe the feature you'd like to see added.

nMaxDbCache was set to 16 GB back in 2015: b3ed423#diff-d102b6032635ce90158c1e6e614f03b50e4449aa46ce23370da5387a658342fd

The UTXO set has been growing significantly over the past few months so we should probably raise it.

Is your feature related to a problem, if so please describe it.

Doing IBD without flushing dbcache is faster. That said, I'm not sure how much one single flush matters.

Describe the solution you'd like

Make nMaxDbCache bigger.

Describe any alternatives you've considered

No response

Please leave any additional context

Much growth recently:
https://statoshi.info/d/000000009/unspent-transaction-output-set?orgId=1&from=now%2Fy&to=now&refresh=5s&viewPanel=8